Recorder with foil electrode moving parallel to recording medium



Nov. 28, 1961 D. SHALL-:R

RECORDER WITH FOIL ELECTRODE MOVING PARALLEL TO RECORDING MEDIUM Filed July 2l, 1958 FIG. 4 2, l), 3 FIG 2.

lTL 26 INVENTOR DAVID SHALER ATTORNEY United States Patent Ofhce r3,010,778 Patented Nov. 28, 1961 3,010,778 RECORDER WITH FOIL ELECTRODE MOVING PARALLEL TO RECORDING MEDIUM David Shaler, Waldwick, NJ., assignor, by mesne assigns ments, to Hogan Faximile Corporation, a corporation of Delaware Filed July 21, 1958, Ser. No. 749,800 8 Claims. (Cl. 346-74) This invention relates to the art of facsimile recording and particularly concerns an yelectrolytie recorder having a novel anode. A n

In recorders of the type employing multiple-stylus disposed in a parallel array there is usually provided a positive metal electrode which is gradually eroded as electric current is passed from the electrode through an electrolytic recording paper to the styli. The anode is gradually eroded while the paper is being marked as the metal of the anode dissolves into the paper. This erosion of the anode is particularly troublesome when the styli are closely spaced and the paper is advanced at high speed because frequent replacement of the anode is required. Also as the anode is eroded uniform contact with the paper surface is lost and the high quality of marking quickly becomes degraded. It has been proposed to provide a metal band or tape which is continuously advanced across the paper in a direction perpendicular to the direction of paper movement. This type of tape arrangement presents a rigid edge to the styli which overlay the edge with the recording paper disposed between the tape and styli.

These moving anodes developed partially eroded pitted edges which were advanced progressively across the paper and became even more eroded as they steadily moved past successive styli in a direction perpendicular/to the direction of paper movement. This progressiveerosion resulted in loss in marking quality unless the band was advanced before marking quality was noticeably degraded. Another suggested solution has been the provision of a positively charged roller which was oscillated androtated while in use.

None of these anode renewal devices includes means for continuously providing each stylus with a fresh noneroded intersecting anode surface. The present invention in one aspect is directed at meeting this need in an economical and simple manner. y

The present invention has -as an object the provision of an improved anode for an electrolytic graphic recorder in which the anode is in the form of a thin metal film or foil. A further object is provision of a metal film or foil electrode with means for advancing the foil so that it alwaysn presents a fresh non-eroded anode surface to the recording paper yand coacting styli cathode.

A further object is provision of a foil electrode in a recorder employing stationary styli, rapidly advancing electrolytic marking paper, and means for slowly moving the foil generally parallel to the direction of movement ofthe paper so that fresh noneroded, unpitted foil anode surfaces are continuously applied to the paper at the marking points of the styli.

A still further objectof the invention is to provide a recorder in which intersecting electrodes provide more precisely delined marking points than hasy hitherto been possible with the marking points retaining their precise dimensions because of continuous replacement of eroded anode surfaces.

In the present invention the foil electrode or metal layer electrode is advanced in one direction parallel to the longitudinal direction of paper movement. The foil may move in the same direction as the. paper or in the reverse direction. In either case fresh points of anode contact are continuously being presented 'to the styli which are disposed in longitudinally parallel spacedarraylacross the paper. The invention will be best understood from the following description taken together with the drawing wherein: y

FIG. l is a front elevational view of a graphic recorder embodying the invention.

FIG. 2 is a sectional view taken on lines 2-2 of FIG. l.

In the drawing there is shown a recorder including a frame formed by a pair of ilat rectangular plates 10 and 12 joined together at one end by bars 14 at their corners and by a plate 11 at the other end. A motor 16 energized via wires 17 is mounted on a bracket 18 by spacers 20 secured by screws 21 to plate 10. This motor has a shaft 22 journaled in sleeve bearings 23, 23' and passing through plates 10 and 12.

The shaft carries a roller or reel 26 extending transversely between the plates. The reel hasr hubsy 24 and flanges 26a secured `by screws 25 to shaft 22.` The reel has a cylindrical sleeve 29 arranged for taking up eroded portions of a metal foil web 30. The foil is stored as a roll 27 on a supply reel or roller 32 having end flanges 32a and arnetal sleeve33 frictionally engaged on shaft 34. This shaft is journaled to rotate in bearings 35, 35' inthe plates 10 and 12. A paper supply roll 36 is carried on a reel 38'having end cores 40 and flanges 38a removably supported in bearings 39 in plates 10 and 12. Roll 36 is disposed in a humidor compartment C formed by side plates 10, 12, end plate 11, top plate 37, bottom plate 43 and partitions 39 and 41. These partitions are disposed in coplanar array and are spaced apart to provide a slit S through which the paper web 52 passes out of the compartment. Plate 37 is removably secured by screws 37a on plates 10, 12. The paper is threaded under a plurality of stationary flexible metal wire styli 42 disposed in a spaced parallel array transversely across the paperwith each stylus extending longitudinally parallel to plates 10 and 11. The s'tyli are liexible members made of stainless Steel or other metal which may be embedded in a plastic or ceramic block 44 mounted on the edges of plates 10 and 12 by screws 46. The marking ends of the styli extend out of one end of the block and their conductive ends 47 extend out of the other end and are individually connected to the negative terminals 48 of marking circuits as indicated diagrammatically by Varrows in FIGS. 1 and 2. A positive electrical potential is applied to the metal shaft 34 from a common positive terminal 50 of the marking circuits. The foil electrode 30 is thus positively charged. The web of foil is threaded underneath a round guide bar 54 which smoothes the foil, and `over a wedge-shaped insulated platen 51 having a tenon 53 inset in a groove in a base plate 56. Screws 59 secure the base plate to the side plates 10, 12. The platen 51 has a very tine edge 57 across which the several styli 42 are pressed with the recording paper and foil disposed between the styli and platen. Styli 42 are so mounted in block 44 that they exert individually spring pressure on the paper web and foil along marking line L where the styli cross the supporting edge 57 ofthe platen. If the foil is very thin of the order of .0005 of an inch (1/2 mil) and the individual styli have diameters of .001 to .002 of an inch (l to 2 mils) it is quite possible to obtain a square markingspot for each stylus on the paper of materially less than .01 of an inch on each side. This marking spot will retain its precisely formed size because the foil anode which tends to erode during use will be continuously withdrawn from the supporting edge 57 at the marking line L. The marking line L has a measurable width determined to a considerable extent by the sharpness of edge 57. Edge 57 can be made as line as desired. Successful recordings have been made with a platen having an .Y edge.

The foil is threaded under another guide and vtensioning bar 55 which has a free end spaced from side plate 12 to permit the foil to be easily threaded under the bar. The foil terminates at take-up roll 31.

The recorder is so arranged that the paper is marked in parallel lines M depending on the signals applied to the various styli via circuits 48. If an appropriate signal is given, as is obvious, and as is well known in the art, a line may be marked transversely o-f the paper, the line being made by a dot produced at each styli, the maximum length of such a line occurs when all of the styli 42 are marking, and the position of such a transversely extending line is ltermed the marking portion. The paper web 52 is advanced by means of a motor 60` energized by wires 63 and mounted by bracket 62 and screws 61 on plate 10. Shaft 64 of this motor is journaled in side plates 10 and 12. The shaft carries a resilient rubber sleeve 66. A11 idler roller having a shaft 6'7 and a resilient rubber sleeve 68 coacts with sleeve 66 for advancing the paper longitudinally in the direction indicated by arrow '70. Motor 60 advances the paper at a very rapid speed up to a hundred or more inches per second. Motor 16 advances the foil electrode 30 longitudinally in the direction indicated by arrow 72 at a much slower speed of the order of a hundredth of an inch per second. The foil can be moved in a reverse direction to that of arrow 72 if desired so that reel 26 becomes the supply reel and reel 32 becomes the take-up reel. In any event the foil moves in a direction parallel to styli 4Z and the direction of paper movement.

It Will he noted that as gradual erosion of the foil takes place in the area A beyond the marking line L the pitted or eroded lines E of the foil advance so that unpitted portions of the foil in the fresh area B advance to `the marking line L. Portions of paper 52 and styli 42 are broken away in FIG. l to show the foil 30 beneath. The foil anode is preferably formed of stainless steel but other thin metal films or foils can be used.

The foil is an inexpensive expendable material and provides excellent black or dark recorded marks when used with electrolytic recording paper of the type described in U.S. Patent No. 2,358,839.

lf desired a rotatable drum carrying a helical electrode can be substituted for the multiple stylus assembly 42, 44. This drum would be carried by plates and 12 and could be rotated by motor 16 or 60' via a suitable gear train. The helical electrode would be disposed to intersect the marking line L. The point of intersection of the foil 30 at edge 57 with the helical electrode would repeatedly traverse the paper 52 along line L while the paper and the foil were advanced in parallel directions. Other types of intersecting stationary or movable electrodes could be used instead of the styli 42 to intersect the marking line for coactio-n with the moving foil electrode on the recording paper.

It Iis possible to use the foil again dter one side ha-s been eroded, by removing roll 31 and placing it on shaft 34 in a reversed position so that the non-eroded side or edge of the foil will be uppermost and facing paper web 52 on the supporting edge 57. For this use, the maximum depth of erosion of the foil should not exceed one half the thickness of the foil. This depth of erosion can be controlled by adjusting the speed at which motor 16 advances the ffoil. If desired a single motor can be used instead of two motors 16 and 60. For example, motor 16 can be replaced by a speed reducing gear train connecting motor 60 with shaft 22.

Since it is desired to limit application of the positive electrical potential to the foil alone, bearings 35, 35', bar 54, platen 51, bar 5S and shaft 22 should be made of electrical insulation material.

This type of recorder may be used Afor telemetering through a plurality of distant signal sources connected to terminals 48 or can be used in any system wheres a plurality of channels are required to be recorded at high speed on an electrolytic recording medium. The marks M can be graphic reproductions of pictures, printed or Written subject matter, or any type of copy normally handled in facsimile communications or graphic copy recording by electrical methods. In the claims, reference to the direction of movement of the travelling erodable electrode as being parallel to the direction of movement of the recording medium is to be understood to refer to any arrangement where the electrode is advanced in the direction of its length in generally the same, or opposite, direction as the direction of movement of the recording medium, regardless of whether or not a portion of such electrode and a portion of the recording medium. should happen to lie in flat parallel planes.

While one embodiment of the invention has been illustrated anddescribed by way of illustration, it will be apparent to those skilled in the art that various modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

What is claimed is:

1. A recorder comprising a yfirst thin metal foil electrode, means for supporting the foil electrode in a recording area, means for moving the foil electrode in one direction past its support, a second electrode, a sheet of electrolytic recording medium in electrical contact with the electrodes in said recording area, and means for moving the recording medium in a direction parallel to the direction of movement of the foil electrode at least through the recording area, said moving means moving said foil at a sufficiently rapid rate that significant erosion thereof with consequent recording deformation is eliminated.

2. A recorder comprising a first thin metal foil electrode, means for supporting the foil electrode in a recording area, means for moving Ithe foil electrode in one direction past its support, a second electrode, a sheet of electrolytic recording medium in electrical contact with the electrodes in said recording area, and means for moving the recording medium in a direction parallel to the direc- Ition of movement of the foil electrode at least through the recording area, the foil electrode having a Width at least equal to the width ofthe portion of the recording medium which is to be marked, said moving means moving said foil at a suiciently rapid rate that significant erosion thereof with consequent recording deformation is eliminated.

3. A recorder comprising a iirst thin metal foil electrode, means for supporting the foil electrode in a recording area, means yfor moving the foil electrode in one direction past its support, a second electrode, a sheet of electrolytic recording medium in electrical contact with the electrodes in said recording area, land means for moving the recording medium in the same direction as the direction of movement of the foil electrode at least through the recording area, said moving means moving said foil at a sufficiently rapid rate that significant erosion thereof with consequently recording deformation is eliminated.

4. A recorder comprising a first thin metal foil electrode, means for supporting the foil electrode in a recording area, means for moving the foil electrode in one direction past its support, a second electrode, a sheet of electrolytic recording medium in electrical contact with the electrodes in said recording area, and means for moving the recording medium in the same direction `as the direction of movement of the foil electrode at least in said recording area, but at a predetermined rate of speed ranging between the same speed as the movement of the electrolytic medium and a speed one ten thousandths of said speed, said moving means moving said foil at a suiciently rapid rate that significant erosion thereof with consequent recording deformation is eliminated.

5. A recorder comprising a first thin metal foil electrode, means for supporting the foil electrode in a recording area, means for moving the foil electrode in one amarre direction past its support, a second electrode, a sheet of electrolytic recording medium in electrical contact with the electrodes in said recording area, and means for moving the recording medium in the opposite direction to the direction of movement of the foil electrode at least through the recording area, said moving means moving said foil at a snliciently rapid rate that signiiicant erosion thereof with consequent recording deformation is eliminated.

6. A recorder comprising a roll of thin metal foil having a portion extending therefrom forming a iirst electrode, means for supporting the foil electrode in la recording area, means for moving the foil electrode in one direction past its support, a second electrode, a roll of electrolytic recording medium having a portion extending therefrom in electrical contact with the electrodes in said recording area, and means for moving the recording medium in a direction parallel to the direction of movement of the foil electrode at least through the recording area, said moving means moving said foil at a suthciently rapid rate that signiiicant erosion thereof with consequent recording deformation is eliminated.

7. -A recorder comprising a roll of thin metal foil having a portion extending therefrom forming a first elecf trode, means for supportingthe foil electrode in a recording area, roller means for moving the foil electrode in one direction past its support, take up roller means for receiving the foil electrode after it has passed its supporting means, -a second multi-stylus electrode, a roll of electrolytic recording medium having a portion extending therefrom in electrical contact With the electrodes,

- 6 and'roller means for-moving the recording medium in a direction parallel to the direction of movement of the foil elect-rode at least through the recording area, said moving means moving said foil at a sumciently rapid rate that signicant erosion thereof with consequent recording deformation is eliminated.

8. A recorder comprising a roll of thin metal foil having a portion extending therefrom forming a rst electrode, a foil smoothing member, means for supporting the foil electrode in a recording .area and having a narrow edge, roller means for moving the foil electrode in one direction past the foil smoothing member and past yits support, the foil being smoothed by the foil smoothing member and the foil conforming to the narrow edge of its supporting means as it passes thereover, take up roller means for receiving the foil electrode after it has passed its supporting means, a second multi-stylus electrode, `a roll of electrol'ytic recording medium having a portion extending therefrom in electric-al contact with the electrodes, and roller means for moving the recording .medium in a direction parallel to the direction of movement of the foil electrode at least throng-h the recording area, said moving means moving said foil at a suiiiciently rapid rate that signiiicant erosion thereof with consequent recording deformation is eliminated.

References Cite-ti in the tile of this patent UNiTED STAFES 'PATENTS 2,615,777 Deuth Oct. 28, 1952 

